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fradrive-old/src/Database/Esqueleto/Utils.hs

328 lines
11 KiB
Haskell

{-# OPTIONS_GHC -fno-warn-orphans #-}
{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
module Database.Esqueleto.Utils
( true, false
, justVal, justValList
, isJust
, isInfixOf, hasInfix
, or, and
, any, all
, mkExactFilter, mkExactFilterWith
, mkContainsFilter, mkContainsFilterWith
, mkExistsFilter
, anyFilter, allFilter
, orderByList
, orderByOrd, orderByEnum
, strip, lower, ciEq
, selectExists, selectNotExists
, SqlHashable
, sha256
, maybe, maybeEq, unsafeCoalesce
, bool
, max, min
, SqlProject(..)
, (->.)
, fromSqlKey
, selectCountRows
, selectMaybe
, module Database.Esqueleto.Utils.TH
) where
import ClassyPrelude.Yesod hiding (isInfixOf, any, all, or, and, isJust, maybe, bool, max, min)
import Data.Universe
import qualified Data.Set as Set
import qualified Data.List as List
import qualified Data.Foldable as F
import qualified Database.Esqueleto as E
import qualified Database.Esqueleto.Internal.Sql as E
import Database.Esqueleto.Utils.TH
import qualified Data.Text.Lazy as Lazy (Text)
import qualified Data.ByteString.Lazy as Lazy (ByteString)
import Crypto.Hash (Digest, SHA256)
{-# ANN any ("HLint: ignore Use any" :: String) #-}
{-# ANN all ("HLint: ignore Use all" :: String) #-}
{-# ANN any ("HLint: ignore Use any" :: String) #-}
{-# ANN all ("HLint: ignore Use all" :: String) #-}
--
-- Description : Convenience for using `Esqueleto`,
-- intended to be imported qualified
-- just like @Esqueleto@
-- ezero = E.val (0 :: Int64)
-- | Often needed with this concrete type
true :: E.SqlExpr (E.Value Bool)
true = E.val True
-- | Often needed with this concrete type
false :: E.SqlExpr (E.Value Bool)
false = E.val False
justVal :: PersistField typ => typ -> E.SqlExpr (E.Value (Maybe typ))
justVal = E.val . Just
justValList :: PersistField typ => [typ] -> E.SqlExpr (E.ValueList (Maybe typ))
justValList = E.valList . map Just
-- | Negation of `isNothing` which is missing
isJust :: PersistField typ => E.SqlExpr (E.Value (Maybe typ)) -> E.SqlExpr (E.Value Bool)
isJust = E.not_ . E.isNothing
infix 4 `isInfixOf`, `hasInfix`
-- | Check if the first string is contained in the text derived from the second argument
isInfixOf :: ( E.SqlString s1
, E.SqlString s2
)
=> E.SqlExpr (E.Value s1) -> E.SqlExpr (E.Value s2) -> E.SqlExpr (E.Value Bool)
isInfixOf needle strExpr = E.castString strExpr `E.ilike` (E.%) E.++. needle E.++. (E.%)
hasInfix :: ( E.SqlString s1
, E.SqlString s2
)
=> E.SqlExpr (E.Value s2) -> E.SqlExpr (E.Value s1) -> E.SqlExpr (E.Value Bool)
hasInfix = flip isInfixOf
and, or :: Foldable f => f (E.SqlExpr (E.Value Bool)) -> E.SqlExpr (E.Value Bool)
and = F.foldr (E.&&.) true
or = F.foldr (E.||.) false
-- | Given a test and a set of values, check whether anyone succeeds the test
-- WARNING: SQL leaves it explicitely unspecified whether `||` is short curcuited (i.e. lazily evaluated)
any :: MonoFoldable f => (Element f -> E.SqlExpr (E.Value Bool)) -> f -> E.SqlExpr (E.Value Bool)
any test = or . map test . otoList
-- | Given a test and a set of values, check whether all succeeds the test
-- WARNING: SQL leaves it explicitely unspecified whether `&&` is short curcuited (i.e. lazily evaluated)
all :: MonoFoldable f => (Element f -> E.SqlExpr (E.Value Bool)) -> f -> E.SqlExpr (E.Value Bool)
all test = and . map test . otoList
-- Allow usage of Tuples as DbtRowKey, i.e. SqlIn instances for tuples
$(sqlInTuples [2..16])
-- | Example for usage of unValueN
_exampleUnValueN :: (E.Value a, E.Value b, E.Value c) -> (a,b,c)
_exampleUnValueN = $(unValueN 3)
-- | Example for usage of unValueNIs
_exampleUnValueNIs :: (E.Value a, b, E.Value c) -> (a,b,c)
_exampleUnValueNIs = $(unValueNIs 3 [1,3])
-- | Example for usage of sqlIJproj
_queryFeaturesDegree :: (a `E.InnerJoin` b `E.InnerJoin` c) -> b
_queryFeaturesDegree = $(sqlIJproj 3 2)
-- | generic filter creation for dbTable
-- Given a lens-like function, make filter for exact matches in a collection
-- (Generalizing from Set to Foldable ok here, but gives ambigouus types elsewhere)
mkExactFilter :: (PersistField a)
=> (t -> E.SqlExpr (E.Value a)) -- ^ getter from query to searched element
-> t -- ^ query row
-> Set.Set a -- ^ needle collection
-> E.SqlExpr (E.Value Bool)
mkExactFilter = mkExactFilterWith id
-- | like `mkExactFiler` but allows for conversion; convenient in conjunction with `anyFilter` and `allFilter`
mkExactFilterWith :: (PersistField b)
=> (a -> b) -- ^ type conversion
-> (t -> E.SqlExpr (E.Value b)) -- ^ getter from query to searched element
-> t -- ^ query row
-> Set.Set a -- ^ needle collection
-> E.SqlExpr (E.Value Bool)
mkExactFilterWith cast lenslike row criterias
| Set.null criterias = true
| otherwise = lenslike row `E.in_` E.valList (cast <$> Set.toList criterias)
-- | generic filter creation for dbTable
-- Given a lens-like function, make filter searching for needles in String-like elements
-- (Keep Set here to ensure that there are no duplicates)
mkContainsFilter :: E.SqlString a
=> (t -> E.SqlExpr (E.Value a)) -- ^ getter from query to searched element
-> t -- ^ query row
-> Set.Set a -- ^ needle collection
-> E.SqlExpr (E.Value Bool)
mkContainsFilter = mkContainsFilterWith id
-- | like `mkContainsFiler` but allows for conversion; convenient in conjunction with `anyFilter` and `allFilter`
mkContainsFilterWith :: E.SqlString b
=> (a -> b)
-> (t -> E.SqlExpr (E.Value b)) -- ^ getter from query to searched element
-> t -- ^ query row
-> Set.Set a -- ^ needle collection
-> E.SqlExpr (E.Value Bool)
mkContainsFilterWith cast lenslike row criterias
| Set.null criterias = true
| otherwise = any (hasInfix $ lenslike row) (E.val . cast <$> Set.toList criterias)
mkExistsFilter :: PathPiece a
=> (t -> a -> E.SqlQuery ())
-> t
-> Set.Set a
-> E.SqlExpr (E.Value Bool)
mkExistsFilter query row criterias
| Set.null criterias = true
| otherwise = any (E.exists . query row) $ Set.toList criterias
-- | Combine several filters, using logical or
anyFilter :: Foldable f
=> f (t -> cs -> E.SqlExpr (E.Value Bool))
-> (t -> cs -> E.SqlExpr (E.Value Bool))
anyFilter fltrs needle criterias = F.foldr aux false fltrs
where
aux fltr acc = fltr needle criterias E.||. acc
-- | Combine several filters, using logical and
allFilter :: Foldable f
=> f (t -> cs -> E.SqlExpr (E.Value Bool))
-> (t -> cs -> E.SqlExpr (E.Value Bool))
allFilter fltrs needle criterias = F.foldr aux true fltrs
where
aux fltr acc = fltr needle criterias E.&&. acc
orderByList :: PersistField a => [a] -> E.SqlExpr (E.Value a) -> E.SqlExpr (E.Value Int)
orderByList vals
= let sortUni = zip [1..] vals -- memoize this, might not work due to polymorphism
in \x -> E.case_ [ (x E.==. E.val u, E.val i) | (i,u) <- sortUni ] (E.val . succ $ List.length vals)
orderByOrd :: (Ord a, Finite a, PersistField a) => E.SqlExpr (E.Value a) -> E.SqlExpr (E.Value Int)
orderByOrd = orderByList $ List.sort universeF
orderByEnum :: (Enum a, Finite a, PersistField a) => E.SqlExpr (E.Value a) -> E.SqlExpr (E.Value Int)
orderByEnum = orderByList $ List.sortOn fromEnum universeF
lower :: E.SqlString s => E.SqlExpr (E.Value s) -> E.SqlExpr (E.Value s)
lower = E.unsafeSqlFunction "LOWER"
strip :: E.SqlString s => E.SqlExpr (E.Value s) -> E.SqlExpr (E.Value s)
strip = E.unsafeSqlFunction "TRIM"
infix 4 `ciEq`
ciEq :: E.SqlString s => E.SqlExpr (E.Value s) -> E.SqlExpr (E.Value s) -> E.SqlExpr (E.Value Bool)
ciEq a b = lower a E.==. lower b
selectExists, selectNotExists :: forall m a. MonadIO m => E.SqlQuery a -> E.SqlReadT m Bool
selectExists query = do
res <- E.select . return . E.exists $ void query
case res of
[E.Value b] -> return b
_other -> error "SELECT EXISTS ... returned zero or more than one rows"
selectNotExists = fmap not . selectExists
class SqlHashable a
instance SqlHashable Text
instance SqlHashable ByteString
instance SqlHashable Lazy.Text
instance SqlHashable Lazy.ByteString
sha256 :: SqlHashable a => E.SqlExpr (E.Value a) -> E.SqlExpr (E.Value (Digest SHA256))
sha256 = E.unsafeSqlFunction "digest" . (, E.val "sha256" :: E.SqlExpr (E.Value Text))
maybe :: (PersistField a, PersistField b)
=> E.SqlExpr (E.Value b)
-> (E.SqlExpr (E.Value a) -> E.SqlExpr (E.Value b))
-> E.SqlExpr (E.Value (Maybe a))
-> E.SqlExpr (E.Value b)
maybe onNothing onJust val = E.case_
[ E.when_
(E.not_ $ E.isNothing val)
E.then_
(onJust $ E.veryUnsafeCoerceSqlExprValue val)
]
(E.else_ onNothing)
infix 4 `maybeEq`
maybeEq :: PersistField a
=> E.SqlExpr (E.Value (Maybe a))
-> E.SqlExpr (E.Value (Maybe a))
-> E.SqlExpr (E.Value Bool)
-- ^ `E.==.` but treat `E.nothing` as identical
maybeEq a b = E.case_
[ E.when_
(E.isNothing a)
E.then_
(E.isNothing b)
, E.when_
(E.isNothing b)
E.then_
false -- (E.isNothing a)
]
(E.else_ $ a E.==. b)
bool :: PersistField a
=> E.SqlExpr (E.Value a)
-> E.SqlExpr (E.Value a)
-> E.SqlExpr (E.Value Bool)
-> E.SqlExpr (E.Value a)
bool onFalse onTrue val = E.case_
[ E.when_
val
E.then_
onTrue
]
(E.else_ onFalse)
max, min :: PersistField a
=> E.SqlExpr (E.Value a)
-> E.SqlExpr (E.Value a)
-> E.SqlExpr (E.Value a)
max a b = bool a b $ b E.>. a
min a b = bool a b $ b E.<. a
unsafeCoalesce :: E.PersistField a => [E.SqlExpr (E.Value (Maybe a))] -> E.SqlExpr (E.Value a)
unsafeCoalesce = E.veryUnsafeCoerceSqlExprValue . E.coalesce
class (PersistEntity entity, PersistField value) => SqlProject entity value entity' value' | entity value entity' -> value', entity value value' -> entity' where
sqlProject :: E.SqlExpr entity' -> EntityField entity value -> E.SqlExpr (E.Value value')
unSqlProject :: forall p1 p2. p1 entity -> p2 entity' -> value -> value'
instance (PersistEntity val, PersistField typ) => SqlProject val typ (E.Entity val) typ where
sqlProject = (E.^.)
unSqlProject _ _ = id
instance (PersistEntity val, PersistField typ) => SqlProject val typ (Maybe (E.Entity val)) (Maybe typ) where
sqlProject = (E.?.)
unSqlProject _ _ = Just
infixl 8 ->.
(->.) :: E.SqlExpr (E.Value a) -> Text -> E.SqlExpr (E.Value b)
(->.) expr t = E.unsafeSqlBinOp "->" expr $ E.val t
fromSqlKey :: (ToBackendKey SqlBackend entity, PersistField (Key entity)) => E.SqlExpr (E.Value (Key entity)) -> E.SqlExpr (E.Value Int64)
fromSqlKey = E.veryUnsafeCoerceSqlExprValue
selectCountRows :: (Num a, PersistField a, MonadIO m) => E.SqlQuery ignored -> E.SqlReadT m a
selectCountRows q = do
res <- E.select $ E.countRows <$ q
case res of
[E.Value res']
-> return res'
_other
-> error "E.countRows did not return exactly one result"
selectMaybe :: (E.SqlSelect a r, MonadIO m) => E.SqlQuery a -> E.SqlReadT m (Maybe r)
selectMaybe = fmap listToMaybe . E.select . (<* E.limit 1)